180,526 research outputs found
van der Waals interaction energy between two atoms moving with uniform acceleration
No full textWe consider the interatomic van der Waals interaction energy between two neutral ground-state atoms moving in vacuum space with the same uniform acceleration. We assume the acceleration orthogonal to their separation so that their mutual distance remains constant. Using a model for the van der Waals dispersion interaction based on the interaction between the instantaneous atomic dipole moments, which are induced and correlated by the zero-point field fluctuations, we evaluate the interaction energy between the two accelerating atoms in terms of quantities expressed in the laboratory reference frame. We find that the dependence of the van der Waals interaction between the atoms from the distance is different with respect to the case of atoms at rest, and the relation of our results with the Unruh effect is discussed. We show that in the near zone a new term proportional to adds to the usual behavior, and in the far zone a term proportional to adds to the usual behavior, making the interaction of a longer range. We also find that the interaction energy is time dependent, and the physical meaning of this result is discussed. In particular, we find acceleration-dependent corrections to the (far zone) and (near zone) proportional to ; this suggests that significant changes to the van der Waals interaction between the atoms could be obtained if sufficiently long times are taken, without necessity of the extremely high accelerations required by other known manifestations of the Unruh effect
Italian horror cinema and Italian film journals of the 1970s
No full textThis chapter focuses on the domestic reception of Italian horror cinema in journals and magazines during the 1970s in order to begin a process of understanding the ways in which the genre was valued, discussed and (less commonly) analysed by Italian critics of the period. Although Italian horror benefited of a considerable amount of scholarship, in fact, little has been written (in English, but also in Italian) about the criticism it aroused, and the way it was used by Italian critics to deal with genres and popular cinema. Compared with the previous decade, which witnessed the blossoming of Bava, Ferroni, Freda and Margheriti’s gothic genre, and the subsequent one, which accompanied the work of Dario Argento as a director and a producer of both his and others' films, the brief but intense season of the cannibal movie and the exploitation films of directors like Fulci, Massaccesi and Lenzi, the 1970s were relatively ‘empty’. Most notably, there were a handful of titles that attempted to emanate the success of The Exorcist (William Friedkin, 1973), the release of an Argento film (Suspiria, 1977) and the production of another (Inferno, 1980), and little more. Nevertheless, if we consider the period in the light of the developments in Italian criticism at the time, the situation changes radically and in fact the 1970s fast become a crucial case study: it permits us to evaluate how horror as a genre is framed within the conceptual and ideological frameworks of criticism at that time, and moreover the ways in which discussion of horror impacts on the birth of a critical and academic tradition
Striking a Balance among Security, Privacy and Competition. The Data Retention and Investigatory Powers Act 2014 (DRIP)
No full textFollowing the ECJ decision that declared the Data Retention Directive invalid, the Data Retention and Investigatory Powers Act 2014 (DRIP) has been enacted. It is not indisputable whether the DRIP gives more powers to the intelligence services at the detriment of both citizens’ privacy and freedom of enterprise or whether it simply clarifies the nature and extent of obligations that can be imposed on telecommunications service providers based outside the UK under Part 1 of the Regulation of Investigatory Powers Act 2000 (RIPA). The article provides news also on Data Retention Regulations 2014, R (David Davis MP and Tom Watson MP) v Secretary of State for the Home Department and the proposed Counter-Terrorism and Security Bill, making some final comment on the balance among security, privacy and competition
Appropriate Similarity Measures for Author Cocitation Analysis
No full textWe provide a number of new insights into the methodological discussion about author cocitation analysis. We first argue that the use of the Pearson correlation for measuring the similarity between authors’ cocitation profiles is not very satisfactory. We then discuss what kind of similarity measures may be used as an alternative to the Pearson correlation. We consider three similarity measures in particular. One is the well-known cosine. The other two similarity measures have not been used before in the bibliometric literature. Finally, we show by means of an example that our findings have a high practical relevance.information science;Pearson correlation;cosine;similarity measure;author cocitation analysis
Synthesis of 2,4,6-trisubstituted tetrahydropyrans via 6-exo selenoetherification of unsaturated alcohols
No full textStereoselectivity, regioselectivity and yields in the 6-exo selenoetherification of four unsaturated diols were found to depend on the stereochemistry of the diols and on the presence of an oxygen atom close to the intermediate seleniranium ring. Silica gel was useful in order to obtain good yields. Reactions performed both under kinetic and thermodynamic control led to the same products.
Stereoselectivity, regioselectivity and yields in the 6-exo selenoetherification of four unsaturated diols were found to depend on several factors such as the stereochemistry of the diols, the nature of the R group, the nature of the counter anion of the PhSe+ species and the presence of silica gel
Realism across borders: The role of state institutions in making Italian neo-realist film transnational
No full textThis chapter consider Neorealism in its strictest historical terms as a phase of Italian film production going from the end of World War II to the early 1950s and focuses on its transnational dimension. First of all we want to reconstruct the transnational story of the discourse about (and of) Neorealism, from the moment preceding its actual existence, the period spanning from the late 1930s to the early 1940s, when the project of a new Italian cinema was designed by a group of young film intellectuals, to the its worldwide diffusion after the war and inclusion among the most vital trends in the “culture of reconstruction” (Hewitt 1989). Then we will focus on the modes of production of a few films that, due to their peculiar characteristics, put Italy in contact with other countries: films that were made through co-production agreements, that represented foreign characters or involved foreign professionals, and whose distribution abroad aroused diplomatic tensions. This will lead us to describe how the governmental institutions that controlled film production – in a context in which State intervention was key to the functioning of the industrial system – established the conditions for realist contents to be staged and diffused, and regulated the amount of cinematic “Realism” authorized in the different films
Roberto Ridolfi, la prosa di uno scienziato fiorentino
No full textstudio dedicato all'opera scientifica di Roberto Ridolfi, illustre studioso del Rinascimento, e in particolare all'uso del linguaggio scientifico nelle opere di R.
313. Noto no kuni
No full textIwao Seiichi, Iyanaga Teizō, Ishii Susumu, Yoshida Shōichirō, Fujimura Jun'ichirō, Fujimura Michio, Yoshikawa Itsuji, Akiyama Terukazu, Iyanaga Shōkichi, Matsubara Hideichi. 313. Noto no kuni. In: Dictionnaire historique du Japon, volume 16, 1990. Lettres N (2), O, P et R (1) pp. 35-36
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